DNA study supports African origin of man

[yiozik]

LINK:
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WASHINGTON - A new genetic analysis of people from around the world adds further confirmation to the African origin of humans. The study of genetic details from 938 individuals from 51 populations provides evidence of how people are related and different, researchers led by Richard M. Myers of Stanford University report in Friday's issue of the journal Science.

The team looked at variations in 650,000 sections of each of the DNA samples, providing a view of the similarities and differences between people in greater detail than had been available previously.

Scientists have long believed that modern humans first developed in Africa and spread from there to populate the rest of the world, a theory strongly supported by the new analysis, the researchers said.

In addition, they noted that residents of the Middle East can trace their ancestry to both Africa and Europe, which they said is logical since the region formed a bridge for movement back and forth between the areas.

Also, they noted, they found a close a relationship between the Yakut population of Siberia and native Americans, who are believed to have migrated from Siberia via a land bridge at a time of lower sea levels.

The research was supported by the National Institutes of Health.

[Prokomenos]

Its quite possible that man did originate from Africa but it does not mean that the first man was black.

[yiozik]

Yes I agree!

[Apollyon]

Originally Posted by Prokomenos
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Its quite possible that man did originate from Africa but it does not mean that the first man was black.

I dont think so....
Black Africans are ,at least 15000 years , back in the dna evolution!!!!true.

[really]

I have trouble thinking that man came from Africa (or any other continent) and went from there to populate the other areas of the world, changing in the process and mutating into the different human "races" that we now have. The differences in humans are more than just the skin colour, there are different facial and bone structures, even in the way we think.

My little theory is that we have different "subspecies" of the human species. It is much like black, brown, white, orange bears etc. I don't think that black bears wherever they lived wandered up the North Pole and became white bears. Same thing for humans, I would say. Not to say that any subspecies is better or worse than another, just different.

Also, with what means could humans travel so far in those prehistoric times? I would tend to think that when the "first" humans in Africa were attempting to expand their horizons further, there might already have been other first humans in existence in other continents.

[Prokomenos]

Originally Posted by really
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I have trouble thinking that man came from Africa (or any other continent) and went from there to populate the other areas of the world, changing in the process and mutating into the different human "races" that we now have. The differences in humans are more than just the skin colour, there are different facial and bone structures, even in the way we think.

My little theory is that we have different "subspecies" of the human species. It is much like black, brown, white, orange bears etc. I don't think that black bears wherever they lived wandered up the North Pole and became white bears. Same thing for humans, I would say. Not to say that any subspecies is better or worse than another, just different.

Also, with what means could humans travel so far in those prehistoric times? I would tend to think that when the "first" humans in Africa were attempting to expand their horizons further, there might already have been other first humans in existence in other continents.

You bring up a valid point about subspecies of human. Its very likely that is the case. If we look at the apes and monkeys we notice that they are all just sub species. The same could be said about humans.

[really]

Or with any other kind of animal "group".

Maybe that could explain why we have so many languages (except languages that are derivatives of the main language streams), I have not researched on the subject but it has always been my question why we have so different languages if we presumably came from the same ancestors.

I wonderif the different types of bears or apes could understand each other.

[yiozik]

Languages just like the human evolution are greatly influenced by its surroundings. It is known for example in linguistics that languages that were developed in the north have more consonants due to climate temperatures. We tend to keep our mouths not as open when it is colder outside in an effort to minimize heat exchange. Similarly languages developed closer to the equator have more vowels. Keeping our mouths open when it is hot helps us to cool down due to increased heat exchange.

[Apollyon]

Originally Posted by really
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I have trouble thinking that man came from Africa (or any other continent) and went from there to populate the other areas of the world, changing in the process and mutating into the different human "races" that we now have. The differences in humans are more than just the skin colour, there are different facial and bone structures, even in the way we think.

My little theory is that we have different "subspecies" of the human species. It is much like black, brown, white, orange bears etc. I don't think that black bears wherever they lived wandered up the North Pole and became white bears. Same thing for humans, I would say. Not to say that any subspecies is better or worse than another, just different.

Also, with what means could humans travel so far in those prehistoric times? I would tend to think that when the "first" humans in Africa were attempting to expand their horizons further, there might already have been other first humans in existence in other continents.

I totally agree with Really.
There are strange issues that come up from times to times.I ll give an example.
In our mythology, there is a reference to giants.Peolpe say this is only a myth.Other people say that during excavations , were found human skeletons of 3 meters high, and an organization removed them and hide them in an unknown place.
Ok, let's accept that the above are fairytales. But what is going on when I watched a documentary tv program of SKAI tv, which was refering to the halflings and giants who lived thousands of years ago in the south-east Asia.And ofcourse there were skeleton remnants found.

[yiozik]

Evolution and natural selection play the biggest role for species continuation. Maybe the “giants” were suffering from what would have been classified today as an extremely active thyroid…..etc…who knows and that is the reason they are not around today. I say this because the following is an article posted yesterday about “hobbit” people that were still around 18,000 years ago. Here is the article and link:


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PARIS (AFP) - Anthropologists have fired another salvo in a feud about diminutive "hobbit" people whose fossilised remains were found in a cave on a remote Indonesian island four years ago.

Combatting a bid to have the hobbits enshrined as a separate branch of the human family tree, they argue the tiny cave-dwellers were simply Homo sapiens who became stunted and retarded as a result of iodine deficiency in pregnancy.

Dubbed after the wee folk in J.R.R. Tolkien's tale, the hominids -- just a metre (3.25 feet) tall and with a chimp-sized brain -- lived around 18,000 years ago on the island of Flores.

The Australian-Indonesian team which announced the discovery in 2004 honoured the cave-dwellers with the name of "Homo floresiensis," or "Man of Flores," to bolster their claim that the hobbits were a new species of human.

They theorised that the little people may have been descendants of prehistoric hominids, Homo erectus, who reached Flores nearly a million years ago.

Marooned from the rest of the world, the hominids evolved a small stature to cope with the available supplies of food. Stone tools and animal remains showed they were skilled in hunting, toolmaking and butchering.

Indeed, the species was so successful, went the argument, that for many years the hobbits lived side-by-side with the bigger-brained H. sapiens -- an idea that implies the two hominids may have been more than kissing cousins.

The theory has ignited one of the fiercest rows in years in the outwardly placid discipline of anthropology, a dispute fuelled by wrangles over access to the site and the remains themselves.

In the latest foray, Australian scientists writing in the British journal Proceedings of the Royal Society B, say the hobbits are H. sapiens who were born without a functioning thyroid, a condition that doomed them to "dwarf cretinism."

As a result, the hobbits would have been severely restricted in growth and mental and motor skills, although not as badly as individuals with microcephaly -- an abnormally tiny brain -- or other neurological disabilities.

"Dwarf cretinism is the result of severe iodine deficiency in pregnancy, in combination with a number of other environmental factors," explains co-author Peter Obdendorf of RMIT University.

"Dwarf cretins grow not much more than one metre (3.25 feet) and their bones have distinctive characteristics very similar to those of the Flores hobbits.

"Our research suggests these fossils are not a new species, but rather the remains of human hunter-gatherers that suffered from this condition."

The study focuses on a dimple in the skeleton called the pituitary fossa which houses the pituitary gland.

In the hobbit skeletons, this depression is unusually enlarged and is a hallmark of so-called myxoedematous endemic (ME) cretins, whose brain size is roughly half that of normal, says Obdendorf.

Other telltales of ME cretinism are a double-rooted premolar teeth, primitive wristbones and a poorly-developed chin, which the H. floresiensis camp claim as signs that the hominids are separate species, the study says.

Previous assaults on the hobbit hypothesis have said the hominids were dwarf H. sapiens, but this is the first to suggest that the dwarfism resulted from diet rather than inbreeding.

Iodine would have been critically absent in the group's nutrition, and the main source -- fish and seafood -- would have been at least 24 kilometres (15 miles) away, on the coast, the study points out.

"Almost all the people who have looked at these fossils have been coming from an evolutionary perspective," said fellow author Charles Oxnard, a professor at the University of Western Australia. "Our idea is that this was an environmentally-caused problem."

The researchers say there is anecdotal evidence from local folklore to back their claim.

The Nage people of central Flores tell tales of ancestors called "ebu gogo" who lived in caves, were short, roughly-built, hairy, pot-bellied and stupid, who stole food, could not cook and had an imperfect language.

"These characteristics are all consistent with ME cretinism," says the study.